[Andrea]

JaZZ, thanks for freeing me from a painfully severe indecision. If I buy it, it'll be the DT880 -- and that's it.

Because, I'm now coming from a long 'immersed' listening with the HD650, and well, I don't seem to know what 'dark' is if this headphone is supposed to sound dark. But, though things are so very well balanced (not bad for such a 'casual' headphone - amp pairing), a bit of added midrange warmth would be the icing on the cake ... that is, the 'emergency' interconnect I'm using is suspect. Perhaps a MIT, or a VDH ... I'll need some meditation.

 

[gerG]

First, I need to report something wonderful! Once I equalized them closer to my liking, there was a transformation. Not just in the spectral balance, but in the image. The image is still between my ears and behind my eyes, but it is closer to a speaker image than I can recall with any other headphones, except maybe the K1000. I can't think of a word for this. The instruments sound sufficiently large, but there is actual distance between them, and stable placement. If I switch off the eq it goes away and I get sound like a stereo system behind me in a small reflective room. I don't know if it is a fluke of the eq, or the nature of the headphones, but it is heaven for a detail freak! Oh, and now they have real bass. Very deep and quick.

Second, Halcyon it is great to hear from you! I hadn't seen you around, so I was afraid that you had escaped (which would violate a law of physics, I think). I appreciate your input (which I agree with) and kind words. I haven't shared some of the more exploratory testing yet. I will, once I figure out what the heck it means! On the sobject of equalized response, I have found that I have a preference for almost flat response. The K1000 deliver pretty close to flat, if you add a sub for the first octave.

Third (I don't have a clue why I am counting, but I can't seem to stop): yada, I no longer own the CD3000. They were not for me. I have an old set of data, but I don't know what vintage. I will dig it up and see if I have HD600 data taken with the same setup. Be careful thinking of headphones in terms of speakers. It is a very different set of constraints and sensitivities. The "room" is now on the same size scale as the driver and the receiver. Plus it has a relatively large appendage of highly complex reflectivity cutting across the space at an angle. The same sort of room reflections happen, but are much tougher to control, and they are at critical frequencies in the hearing range. I am trying to devise some measurements that separate the raw headphone behavior from the interactive behavior when on the head. Lots of things to try

Fourth, back to the music. G'night.


gerG

 

[10068]

I am probably not really qualified to add my opinion to this thread

But.. to my ears, on Iron_Dreamer's system... the SA5K sounded like a CD3K w/ silver cables.

Why all the fuss??

 

[Iron_Dreamer]

gerG, care to share the magical EQ settings with us?

 

[10068]

Quote:

Originally Posted by Iron_Dreamer gerG, care to share the magical EQ settings with us?

Yeah I bet you are drooling right now huh

 

[Iron_Dreamer]

Quote:

Originally Posted by Sduibek Yeah I bet you are drooling right now huh

Well not exactly, as they hardly sound like "a stereo system behind me in a small reflective room" to me as they are, so perhaps his EQ would even make them sound better to me, I am just interested to hear what he percieved as a major improvement.

 

[Yada]

Hi gerG,

I'm not surprised that you like flat - or that flat yields other sonic virtues. While it is popular for people who are into audio equipment to say things "I don't like flat", I'm not sure that all those people truly know when they are listening to a system and room that is flat.

I'm not sure that everyone understands what we mean by flat. To be clear, if a system is assembled (source, amp, preamp, speakers - for example) and the music is played in a room (as speakers normally are) we can measure the frequency response of the system plus room by placing a microphone where the listener would normally sit. We can then generate and play various types of signals (such as pink noise or other test signals) at discreet frequencies one at a time (first 32 Hz, then 100 Hz, then 1K Hz, then 4 KHz, then 12 Khz, then 20 Khz for example - or all together in a "sweep") at a specific Sound Pressure Level (80 dB for example). In a flat system the microphone would receive 80 dB and 80 dB would be recorded/reported on a spectrum analyzer for each of the generated frequencies. I realize that measuring headphones is somewhat different than measuring speakers (that's why I was interested in how gerG is testing), but the goal is the same - to characterize the equipment plus the acoustical environment.

In laymans terms, all this means is that tones inputted to the system at a certain volume level should be outputted by the system at the same volume level. In other words, the system and room shouldn't emphasize or de-emphasise any tone. If the system plays the tones faithfully, then the system is "flat". When a system and room deviate from this, then the system plus room have modified the signal, which means that the system and room are modifying all the music being played. Why would we want to have a system and a room (or headphones) that arbitrarily changes the sound of the Beatles or Beethoven? I don't think we would, unless we either just settle for what we throw together, or worse, if we talk ourselves into the notion that we "don't like flat".

And it's not just the frequency (tonal) response that is being randomly adjusted. When the combined equipment plus room (or headphone) environment is assembled (or EQ'd) to produce a flat response not only will the bass start to sound right, along with the midrange and the highs, but also all the subtle but compelling attributes we search for in "high end" systems will begin to appear at newly discernible levels.

I don't think it's a coincidence that gerG found that flat not only provided a pleasing tonal response, it also surfaced a bunch of "cue" information that is present in many, many recordings, but which is missing in improperly designed equipment or improperly setup systems. Air, transparency, detail, and sound stage imaging are able to surface because frequencies are no longer stomping on each other, and they are no longer being improperly absorbed or reflected by walls or other environment surfaces. This results in a better sense of timing and space for the listener.

If you go over to audiogon.com, which is to 2-channel hifi what head-fi.org is to headphone systems you will see tons of experienced Agoners say that "synergy" is a key to getting high end results. Translated into headphone speak, synergy means that if you think your Sony headphones are too bright you should get a warmer amp, or if you think your Sennheiser headphones are too warm you should get a brighter amp. While it's useful to balance system components in this regard, I think it's best to choose the most critical components first (speakers or headphones) with a view toward picking the most accurate transducer in your price range. Then you should select the rest of the components in a way that creates synergy - but by picking the most accurate transducer first you will need to offset fewer sonic degradations with the synergistic approach. In this manner you avoid compounding problems. While this is a practical approach, the ideal nonetheless starts with flat - and as Yogi Berra said, "if you don't know where you are going, you might wind up somewhere else."

I'm simply suggesting that whether head-fiers recognize it or not, people who spend the time and energy to read and post to this site are looking for flat. If you can't get comfortable with the concept of flat, then substitute the word "accurate." Again, if you think you can make the Beatles or Beethoven sound better than their original music, then you don't really want flat. Personally, I'm inclined to stick with the original artists. Having said that, I'm sure there are always exceptions, but before you declare flat to be the wrong direction, give it some consideration.

In any event, gerG, it would be great to see the frequency plots for the SA5k and CD3K (if possible) vs. the 650. At the end of the day, everyone has different equipment, rooms or listening environments, and their own personal tastes - and everyone is entitled their preferences. I'm just looking for a way to achieve what I believe is possible - a system that will play a wide range of music genres in a way that accurately reproduces what the original music sounded like when it was recorded. Personally, I believe that if the frequency response of the individual components is taken into consideration along with the acoustical environment (the room for speakers, or the headphone design for headphones), it is possible to achieve one system that makes most music sound real and pleasing. Once I've got one system sounding as real and pleasing as possible, then it might be fun to go for a variant, if it's still needed. Personally, I think the real value of having two components at the same time is to compare the two, sell the loser, and make room for a new contender. At the same time, I don't begrudge the method that says "since we can't get one system to sound right for most music, we'll simply have multiple systems". Whatever works for you.

 

[seeberg]

Quote:

Originally Posted by devwild I'd say springing for a higher model would be better bang/buck than recabling an SA1000, particularly with the bass differences. I have to admit, I've found myself wondering if a recable would be possible, the cable on the SA5000 is a little awkward. But that's a mechanical issue, like why I wish to DIY recable my 595s, and not sonic... not somewhere I wish to spend $250+ I will try an poke someone and see if my smile would be "acceptable"

Does the cable detach on any of the SA's or Qualia?

Me, personally, I think I'd be content with the quality of the stock cable, especially if it is anywhere near the quality of the Grado extension or the Cardas HPI. Any thoughts on that?

...And of course, here's to hoping your smiley makes it in.

,
Abe

 

[halcyon]

"Flat" is a misnomer.

If we use it loosely to mean "linear" (i.e. non-distorting) sound reproduction device, then I agree with you completely.

That's one of the goals that audio reproduction engineers aim for: the truth in audio reproduction. Reproduce the recorded signally with as little of distortion as possible (in terms of signal theory).

However, even in this scenario there is a known (but unexplainable) discrepancy between linear components and the actual experience of listening to them.

Not all "flat" devices (using the term loosely here, as described above) sound equal. Also, some of them sound worse than "non-flat" devices. This cannot be explained fully and without any room for error using known acoustic/psychoacoustic science of today. Or if it can be done, I'd very much like to receive a reference to a scientific literature that explains this.

Now, the second meaning for the term "flat" refers to it's spectral output: namely that it measure absolutely flat in it's amplitude response (as a function of frequency), when measured acoustically (not just electrically).

However, and this is a big however, headphones do not measure flat when they are "ideal".

Why?

Because:

1) The point at which headphones are measured (concha, entrance to ear canal) is not "flat" in the human ear. If you don't wear headphones, but just wear microphones at concha level and record sounds from absolutely flat speakers (in a diffuse field or anechoic chamber), then the sound at your concha level is not flat anymore. The graph will NOT look like a straight line.

This is due to what is overall called a head related transfer function, which takes into account the torso, head (including hair) and outer ear reflections and masking.

This is "natural" at it's best. You can't get more natural than that frequency response curve at your concha level. The sound gets even more distorted as it enters the ear canal (and then ot middle ear and inner ear), but for the sake of simplification we'll leave it out of the discussion now.

That response (and related HRTF) is also individual to every single living person.

No two persons hears one sound exactly the same, although there is a high degree of agreement on what the sound sounds like (probably due to neural matching at higher cognitive levels of auditory processing).

2) Second reason why ideal headphones do not measure flat is because with headphones on, one is measuring a head+headphone coupled system. Not just the headphone.

If one designs headphones so that they are ideal in their frequency response when not worn, they will not be ideal anymore when worn, due to the reflective chamber that the head+headphoen produces. A good headphone designer takes this into account and designs the headphone to sound best (not flat, but ideal in terms of generic/averaged HRTFs) when worn.

So, in summary:

- an ideal (in terms of best known acoustic measurements correlated with listening test) headphone graph when measured from entrance to ear canal (on a person's head, i.e. worn) is not a straight line (i.e. not "flat" in that sense of the word).

- designing/measuring headphones to be flat at that position will make them sound unnatural. Yes, it's possible to make them more "reavealing" this way due to the masking effect of human hearing.

However making them more revealing will reveal things on a recording that a human listener would NOT be able to hear in a normal acoustic setting. This is what I sometimes call personally the desire of the Hyperreal or desire to augment senses beyond what they are naturally capable of (like x-ray acoustics). Also, the process will simultaneously mask other frequencies, that were earlier audible before. That is the nature of human auditory system and cannot be mechanically avoided (maybe with some neural implants in the future, but even then it begs to ask the question: "why? for what use?").

These two things are just some of the small things why (IMHO) making snap judgements about flat frequency response curves can be very misleading indeed.

In headphone measurements, flat is not "ideal" (in objective scientific terms).

It can however be most pleasing to some people. We all like many different things, after all.

regards,
halcyon

PS Thanks for the welcome back greetings gerG! don't have that much time for headfi these days, but I try to pop-in every now and then to see your new measurements

 

[Yada]

Sovkiller, if I understand you correctly, your point is that the human hearing system has some peaks that are inherent in our "ear design". In other words, if we were to play for a human a perfectly flat signal from 20-20kHz the human wouldn't hear flat but rather the human would "hear" the curve you posted, right?

Well, that doesn't mean we won't like a system that is flat, but rather it means that if we hear a flat signal we will get sound that is shaped like your curve.

The purpose of designing a flat system (with inherently flat equipment and/or with an equalizer to keep or make the system flat in an acoustical environment - as in a room or with headphones on) is so that any music we feed into the system will come back out of the system as it went into the system.

Our ear system - as you point out is going to be consistent in how it modifies sound - so what we are looking for is a system that DOESN'T MODIFY the signal created by the original musicians. In that way we will hear the music as it was intended by the musicians rather as modified by the system.

Just a thought for you to consider.

------
From Sovkiller:

"For the ones looking for flat responses on headphones, remember that this is not the way to go, don't forget the biophonic curves:

Those are based on human measuments, and on real studies, IIRC is the result of the freq resonances of the human hearing canal or cavity, and you will hear, with a flat curve, some peaks that you have to consider....."

 

[Yada]

Hi Halcyon,

Just to be clear, I don't think headphones measuring flat by themselves are any more of a full solution than are speakers and amplifiers measuring flat by themselves. In order for a speaker system to truly sound flat the room acoustics need to taken into consideration. I can say that based on a substantial amount of experimentation with measurements in a speaker plus room based system using TrueRTA at 1/24 octave resolution that I have found the results to be most appealing when the SYSTEM PLUS THE ROOM are EQ'd to flat. Admittedly, that could be my preference, but I also observed that when flat was achieved the subtle cues such as definition, detail, transparency, air, and sound stage imaging all were at their best when the system was set to flat.

My theory is that when frequencies don't stomp on each other and room reflections and aborptions are controlled then the detail within the music can best be resolved by our hearing. in other words, when the system plus room is flat other subtle but imortant cues regarding time and space are best revealed which results in a more accurate reproduction of the recorded music. To me, the purpose of a music system (speaker or headphone-based) is to accurately hear the original music as it was intended, not to change an artist's music.

Taking the above discussion from speakers and rooms to headphones and heads, I believe the goal then is not to test headphones for flatness by themselves, but rather when they are installed on a head - I believe you use the term "coupled" to describe this condition. I think coupled is a fine term.

I believe that if it is possible to measure the coupled condition that flat would be desirable in the sense that flat would at that point mean that we are hearing the various frequencies at the same amplitude relative to one another - just as they were fed into the system at the source device.

To reiterate, as I mentioned in my post to Sovkiller above, I believe the human hearing system has it's own characteristics. And as you point out, there is some variation from human to human - although I believe that in very large populations we have more similarities than differences. Nonetheless, the point of making a flat system in a coupled envniroment (ie an environment in which we take into consideration both the system and the acoustical environment) is that we will then be able to hear the music with the same attributes that were originally recorded on the source material.

My ears may change the amplitude of various frequencies because of how they were designed and how they operate - but they do that consistently to all sound in the same acoustical environment; they may treat headphones different than speakers in a room, but for a given headphone design or a given room our ears operate the same. IE, our hearing is constant (obviously over time our hearing evolves, but I'm talking about within any given day).
Again, for the sake of this discussion, our hearing is constant in a constant acoustical environment.

Next, the musicians made some music with various frequencies at various amplitudes. So, the music is a constant.

To repeat, our heaing is constant and a recording is constant. So, what we are looking for is the combination of electronics plus an acoustical environment that is also constant AND THAT DOESN'T CHANGE THE ORIGINAL RECORDING BEFORE IT GETS TO OUR EARS. It is simple - taking both the electronics and the acoustical environment into consideration, what we output from the Beetles or Beethoven we would like to input to our ears. By definition, that is flat.

 

[JaZZ]

Quote:

Originally Posted by Yada ...our hearing is constant and a recording is constant. So, what we are looking for is the combination of electronics plus an acoustical environment that is also constant AND THAT DOESN'T CHANGE THE ORIGINAL RECORDING BEFORE IT GETS TO OUR EARS. It is simple - taking both the electronics and the acoustical environment into consideration, what we output from the Beatles or Beethoven we would like to input to our ears. By definition, that is flat.

It's really hard to get a constant acoustic environment with headphones -- see the different graphs from HeadRoom, Stereoplay and gerG and their deviations, caused by different measuring arrays. Speakers are much easier to judge, although, as you stated, the interaction with the room has to be taken into consideration. But headphone listening is fundamentally different from speaker listening in that headphone and ears form an interactive system: there are reflections between earpiece/driver and ear. Add to this that the ear shape has a considerable impact in this context. Furthermore the measuring has to be done at the eardrum (of a dummy head) to comprise the whole system and thus has to be reinterpreted according to the HRTF function. Take into consideration that the frontal sonic impact from a speaker causes a considerable distortion of its formerly flat frequency response which can't be satisfactorily reproduced with headphones, neither with diffuse-field nor with free-field equalization, apart from the fact that it's impossible to avoid FR irregularities in the upper range caused by interferences from multiple reflections between driver and ear which aren't completely controllable and moreover ear-shape dependent. In other words: the same headphone will sound different to different persons.

 

[10068]

Quote:

Originally Posted by Yada Sovkiller, if I understand you correctly, your point is that the human hearing system has some peaks that are inherent in our "ear design". In other words, if we were to play for a human a perfectly flat signal from 20-20kHz the human wouldn't hear flat but rather the human would "hear" the curve you posted, right? Well, that doesn't mean we won't like a system that is flat, but rather it means that if we hear a flat signal we will get sound that is shaped like your curve. The purpose of designing a flat system (with inherently flat equipment and/or with an equalizer to keep or make the system flat in an acoustical environment - as in a room or with headphones on) is so that any music we feed into the system will come back out of the system as it went into the system. Our ear system - as you point out is going to be consistent in how it modifies sound - so what we are looking for is a system that DOESN'T MODIFY the signal created by the original musicians. In that way we will hear the music as it was intended by the musicians rather as modified by the system. Just a thought for you to consider. ------ From Sovkiller: "For the ones looking for flat responses on headphones, remember that this is not the way to go, don't forget the biophonic curves: Those are based on human measuments, and on real studies, IIRC is the result of the freq resonances of the human hearing canal or cavity, and you will hear, with a flat curve, some peaks that you have to consider....."

I believe Markl has more information about that "human frequency response curve"

 

[halcyon]

I'll try it one more time, really simple (because I'm feeling we are talking about the same thing, but just using different words).

When measured at entrance to ear canal, ideal flat headphones would _on the average_ measure something like this:

And NOT like this:

That's according to the best available scientific literature on acoustic measurements on how human hearing works.

This is the reason why I wanted to point out the use of the term "flat", which can be misleading.

Clearly the lower graph is visually flat. However in terms of accurate/natural response it is distorted when we talk about measurements at human concha level.

Regardless of what the scientific literature says our hearing/opinion doesn't always agree.

That's why we are in disagreement as to which headphone is good, bad, best, crap, etc.

And that's why they keep cramming out new headphones and we end up buying them

regards,
halcyon

 

[sonance]

To add to the discussion about the qualities of equalization, keep in mind that often measurements of dips are related to resonances. That is to say aht some parts of the enclosure or mechanical parts of the drivers are absorbing energies around their natural resonating frequency and resonating at that freq. Even if you do equalize the sound, fundamental harmonics around the natural resonating freq. will still excite resonances, despite measured flatness at the actual resonating dip. This causes audible distortion or harshness.
Old problems with analog equalizers or crossovers which performed additional corrections besides basic high-pass / low-pass is they affect the phase response at correction frequencies and they also affect rise time. Luckily digital equalizers do not have this effect.
Just something to keep in mind when thinking about equalization and what it compensates for.